Posthole digger



April 22, 1941. a J. VANCE POSTHOLE DIGGER 3 Sheets-Sheet 1 Filed May 26, 1939 .5. J. Vence.

A ril 22, 1941. 'p J. VANCE 2,2 ,0

K POSTHOLE DIGGER Filed May 26, 1959 3 Sheets-Sheet 2 ,A ril 22, 1941. J. VANCE 2,239,024

'POSTHOLE DIGGER Filed May 26, 1939 3 Sheets-Sheet 3 fzg J 1 252 g Patented Apr. 22, 1941 UNITED STATES PATENT OFFICE- 1 Claim.

This invention relates to an improved posthole digger and has, for one of its objects. to provide a machine of this character which will effectually excavate postholes and which may be readily attached to and detached from a conventional farm tractor.

Another object of the invention is to provide a posthole digger which is adjustable so that postholes of various depths may be dug.

A further object of the invention is to provide a posthole digger which will be driven from the power take-oil of the tractor.

Other objects of the invention not mentioned hereinbefore will become apparent as the description proceeds.

My invention is illustrated in mg drawings, wherein:

Figure 1 is a side elevation, partly in section, of my improved posthole digger,

Figure 2 is a vertical sectional view on the line 2-2 of Figure 1,

Figure 3 is an enlarged detail sectional view showing a portion of the raising and lowering mechanism, r

Figure 4 is a vertical sectional view on the line 4- -4 of Figure 3,

Figure 5 is a transverse sectional view on the line 5-5 of Figure 3, and

' Figure 6 is an enlarged detail vertical sectional view of the drafting mechanism employed.

Referring now to the drawings wherein like numerals of reference will be seen to designate like parts throughout the views, the numeral i indicates in general a tractor which is of the type commonly employed by farmers and the like. The

the accompany- 7 rear bar of the frame I bearing sleeves i 5 and IS. The bearing sleeves i5 and ii are mounted in spaced relation on the by means of bolts l1 and I 8 respectively.

As best seeen in Figure 1, the side members It) and II of the supporting frame 3 are bent outwardly at l9 and are bent downwardly at 20 to define a bearing guide mounting for a bearing guide 2 I The bearing guide 2| is of substantially loop-shape and carries a guide sleeve 22 therein. Suitable bolts 23 connect the bearing guide 2| with the mounting 20 of the frame 9.

Carried on the frame 9 is a substantially U- shaped outwardly bowed gear supporting bracket 24'. The gear supporting bracket 24 is mounted above the supporting yoke I2 and has its opposite ends bolted to the lower end portions of the side members In and l I. At its mid portion the bracket 24 has an integral vertically extending sleeve 25 which is vertically aligned with the mounting 2|. The sleeve 25 has a guide member 26 therein. Mounted on the supporting yoke l2 medially of its bite portion is a bearing 21. The bearing 21 journals a stub shaft 28 to the free end of which is keyed a beveled driving gear 29. At its opposite end the stub shaft 23 carries a section 30 of a universal 3|, The other section 32 of the univ'ersal 3| is mounted on a'driving sleeve 33 which is provided with a squared opening 34 throughout the major portion of its length. Received in the squared opening 34 is a driving shaft 35 which is connected at its lower end with a universal 36.

tractor l includes wheels 2 and 3 which are connected by an axle housing 4, which is connected at its free ends todriving hubs I and 6. In order to provide a mounting for my improved posthole digger, I provide a substantially U-sha'ped frame member I which has side portions .8 connected to the driving hubs 5 and 6. As will be seen in Figure 1, the portions 3 extend chordally with respect to the driving hubs with the result that the frame I will be rigidly mounted in position on the tractor, The frame member extends rearwardly to a point rearwardly of the wheels 2 and 3.

My improved posthole digger includes a supporting frame which is indicated in general by the numeral 3. The frame 9 includes side members i0 and l l which are connected at their corresponding lower ends with the arms of the U-shaped supporting yoke i2. Thesupporting yoke has its corresponding lower end portions turned laterally to define trunnions I 3 and I4 which are journaled in The opposite side of the universal 36 is connected with a power take-ofi shaft31 which is connected with the tractor transmission. The cooperating sleeve 33 and driving shaft 35, as will be hereinafter set forth, provide an adjustable driving connection for my improved posthole digger. A clutch may be mounted on the stub shaft 23 and will serve the purpose of allowing automatic stopping of the machine when a large rock or the like I is encountered.

In order to effect the actual dig ing of the postholes, I provide an auger 38. .The auger 38 has a ground-engaging screw 33 and a relativelylong squared shank.- The squared shank extends through the member 26 and the sleeve 22 and extends well above said sleeve 22. At its upper end the shank 40 is mounted in an upper sleeve 41 which is rotatable in a guide arm 42 which forms part of a lifting frame 43. A lower guide arm 44 has a sleeve member 35 fitting about the shank 40 near its lower end. A set screw 45 locks the raising frame 43 to the shank 40 so that the frame and shank will be movable in unison. The frame 43 has a vertically extending rack I! which extends substantially parallel to the shank Ill. The rack, as best seen in Figures 3 and 4, includes side members l8 and 58 which are connected by a plurality of equally vertically spaced studs 58 which, of course, define rack teeth.

For shifting the frame 43, with the auger 38, I provide a lifting gear which has teeth engageable in the teeth of the rack 41. The: gear Si is supported by a lifting frame 52 which comprises side plates 53 and 5-", said side plates being mounted at their inner corresponding ends, on the side members it] and H of the'supporting frame 9. As best seen in Figure 5, the side plates 53 and 54 are provided with bowed portions 55 and 58, which extend about the shank 4c, and parallel portions 51 and 58 between which is mounted the gear 5!. The gear it has a mounting shaft 59 with a squared outer portion Connecting with the portion 60 is a crank d l, rotation of which will, of course, effect rotation of the gear El, with consequent raising or lowering of the frame 63 and auger 38. Outwardly of the gear 5! and the rack M between the sections El and 58, there is also a. roller 62. The roller 62 is rotatably mounted on a bolt 63 which extends through the outer end portions of the sections ti and so and has treads 65 which bear against the sides i8 and 49 of the rack 41. The roller 62 thus operates to keep the raclr 6! in proper operative relationship with the gear 5! so that raising and lowering of the frame 43 by the crank 9i will always be possible.

Mounted on the shank ii) of the auger iii is a. driven beveled gear which has a squared sleeve 68 receiving slldably therethrough the squared shank so that said driven beveled gear will permit vertical sliding movenie it of the auger 38 and yet, at the same time, prevent rotation of said gear 65 with respect to the shank cc. The beveled rear 85 will with the beveled driving gear 29 at all times and will be driven thereby. As best seen in Flame 6 of the drawings, the gear 55 rests upon the upper face of the member-1!.

In order to retain themachine in. a given set position, I provide a bracing rod =53 which is connected between the driving huh l and a portion oi the guide member id of the supporting frame 9. I

It is believed that the operation of the machine will be understood from the foregoing descrlption. However, a brief summary is not thought to be out of place.

After the machine has been attached to a tractor, as heretofore described, and the sector is moved to a position for a posthole dissins operation, the power is traitted to the driving shaft I5 and sleeve 33 and thence to the gears 28 and 65. Rotation of the auger as take place and, when the crank M is moved for lower- Gil respectively,

3 power ing the frame and auger 38, an earth-boring operation will take place. The crank 8! may be rotated for lowering the frame and anger to such an extent that a posthole of the desired depth may be dug. Rotation of the crank 68 in an opposite direction will, of course, effect raising of the auger 38 from the ground. After this is done, the tractor may, of course, be moved to the next position.

It will be understood that the entire machine may be swung to various angles with respect to p the ground. The machine is swung on thetz'unnions l3 and N, in the bearings is and i5. The

swinging movement is, furthermore, permitted by the telescoping driving shaft i5 and sleevedi. The rod 61 will, of course, be adjustable for permitting such changes in position of the machine with respect to the tractor. 2

It is particularly desired to call attention to the fact that the machine may be readily attached to and detached from anordinary farm tractor. It is further desired to state that the machine is simple in construction and capable of manufacture at reasonable cost. Further olescription is believed unnecessary.

Having thus described the invention, claimed as new is:

In a posthole digger, having side members'a guide mounting carried by the supporting frame at the upper end of said side membersa mounting sleeve in said guide mounting, ages-r supporting bracket car ried by the side members and having a sleeve, 2. guide member in the sleeve and in vertical what is alignment with the first-mentioned sleeve, a sup-' porting yolre on the frame and having:

Ermnions, a frame member connected to a tractor, bearings carried'by the frame member and journaling the trunnicns, a hearing carriedby the supporting yoke, a stub shaft rotatable in the bearing, a beveled driving gear carried the stub shaft, a universal, a drive sleeve connected to the universal, said universal also be connectedto the stub shaft, a drive shaftthe sleeve, means connecting the drive shaft with a take-oil, an auger having an earth-engaging screw and a shank, said shank helm; elidablo through the guide member and sleeve, a lifting frame carried by the shanlrand having a rash, a lifting gear, a lifting frame mounting the gear for engagement with the rack, said lifting frame being carried by the supporting frame, and a crank carried by the lifting gear and being can gageable for shifting the lifting frame and anger 'a supporting frame 

